Positive displacement compressors include structure for circulating lubricant to parts requiring lubrication. Commonly the lubricant is pumped to the structure requiring lubrication and subsequently drains by gravity to the oil sump. In open drive systems the shaft extends through the housing with the oil in the shaft seal cavity coacting with the shaft seal to provide a fluid seal. In the case of refrigerant compressors, refrigerant is present in the oil due to an affinity between oil and refrigerant. Accordingly, if the seal is compromised by the draining of oil from the shaft seal cavity or due to dilution of the oil due to condensing refrigerant, refrigerant may leak through the seal into the atmosphere.